The visitors won by three goals to one after Dedryck Boyata, Moussa Dembele and Scott Sinclair answered Kyle Lafferty’s 18th minute opener.
However, the Parkhead boss was heavily critical of the playing surface in the immediate aftermath, saying it forced his team into changing the way they play as they struggled to get to grips with their hosts in the early going.
He told BT Sport: “We couldn’t play our normal game today. The pitch, I’m actually a little embarrassed with to be honest, for Scottish football and the standards you’re trying to create throughout the country.
“The pitch was so long the players couldn’t pass on it, and that’s both sides. Guys like Steven Naismith, being in the Premier League all their days, you couldn’t pass the ball.
“But you’ve got to find a way to win and the players did that.
“I thought after the first 10-15 minutes, where the guys were having to get used to playing a different game, it was a great response to going behind.”